Amgen has received both good and bad news regarding the recommended approval of its eagerly anticipated osteoporosis drug Prolia (denosumab) in the USA.

On the plus side, a US Food and Drug Administration advisory panel has recommended the agency approve the drug for treatment of osteoporosis in post-menopausal women and for the treatment of bone loss in men undergoing hormone ablation for prostate cancer.

However, the Advisory Committee for Reproductive Health Drugs did not support the approval of the drug to treat or prevent bone loss in women with breast cancer undergoing hormone ablation or to prevent bone loss in low-risk patients in any of these groups.

The Committee claimed there was not enough data yet for it to support a preventative indication.

Meanwhile, the panel also suggested the drug be limited to women who have tried other treatments until long-term safety data is available, while also citing concerns the drug could hasten tumour growth, thereby recommending against the use of the drug in breast cancer patients with osteoporosis. The panel have recommended a risk management plan.

The cautious approach to denosumab follows a memo posted on the FDA’s website on Tuesday that noted there were a number of safety issues associated with the drug that had been highlighted in trials, including infection, development of new malignancies, “the potential for tumour progression in patients with cancer”, and possible suppression of bone remodelling.

In a statement, Amgen said patient safety was its top priority. The company has proposed a comprehensive post-marketing surveillance programme, including extension of studies in the osteoporosis and oncology settings while also proposing an observational study using healthcare databases.

The FDA is due to make a decision on the drug by 19 October.